Dementia is a clinical syndrome characterized by impairment of multiple higher cortical functions that include memory, orientation, thinking, comprehension, calculation, capacity for learning, language, judgment, executive function and visuo-spatial function. It is usually accompanied or preceded by deterioration in emotional control, social behavior or motivation.
Alzheimer's disease is the most common cause of dementia. Sporadic cases usually present after >60 year while familial types are rare and present in <60 year of age (early-onset dementia).
Short-term memory loss is the most common early symptom. Other spheres of cognitive impairment manifest after several years.

Although the conversion rate of ocular (OMG) to generalized (GMG) myasthenia gravis in Asian patients is low, thymoma and acetylcholine receptor (AchR) antibodies as well as positivity in repetitive nerve stimulation (RNS) studies all predict such generalization, a recent Singapore study has shown.